To the Editor: We greatly appreciate the interest in our article assessing depressive symptoms and illness severity in persons with multiple sclerosis. We agree that new measures of disease severity and disease-specific disability, such as the Multiple Sclerosis Functional Composite, are quite promising and will be important additions for future multiple sclerosis outcomes research. A major limitation of the Expanded Disability Status Scale is the bias toward locomotor function, and newer instruments attempt to capture important realms of cognition and arm and hand function. We chose the Expanded Disability Status Scale for our study, however, for two reasons. First, the Expanded Disability Status Scale is still used as the primary outcome for disability in most multiple sclerosis clinical trials. Second, the Multiple Sclerosis Functional Composite must be administered by a technician, as it includes a timed walk test, a nine-hole peg test, and the paced auditory serial addition test. This makes it unsuitable as a self-report survey instrument that is mailed to a large sample of subjects, as was required by the design of our study.